Dynamic hysteresis from zigzag domain walls

TL;DR

This paper models dynamic hysteresis in ferromagnetic thin films with zigzag domain walls, showing that a single domain wall can explain experimental hysteresis behaviors without nucleation.

Contribution

Introduces a discrete model for domain wall motion in disordered ferromagnets, incorporating dipolar interactions and anisotropy, validated by Monte Carlo simulations against experimental data.

Findings

Good agreement with experimental coercive field data

Hysteresis explained by a single propagating domain wall

Model captures effects of frequency and temperature

Abstract

We investigate dynamic hysteresis in ferromagnetic thin films with zigzag domain walls. We introduce a discrete model describing the motion of a wall in a disordered ferromagnet with in-plane magnetization, driven by an external magnetic field, considering the effects of dipolar interactions and anisotropy. We analyze the effects of external field frequency and temperature on the coercive field by Monte Carlo simulations, and find a good agreement with the experimental data reported in literature for Fe/GaAs films. This implies that dynamic hysteresis in this case can be explained by a single propagating domain wall model without invoking domain nucleation.